The disclosures herein relate generally to fluid interconnections and more particularly to fluid interconnections for a machinery casings used as pressure vessels.
The machinery casing of centrifugal compressors are commonly used as pressure vessels. For example, the DATUM line of compressors manufactured by the Turbo Products Division of Dresser-Rand use the machinery casing as a pressure vessel. In addition to serving as a pressure vessel, the machinery casing may also serve as the structural frame. Various components of the compressor are mounted on or machined into the interior and exterior surfaces of the machinery casing. Items such as stationary flowpath components are attached to an interior surface of the machinery casing. The location of these items can be critical to the performance and operation of related components of the compressor. It is essential that features formed through the machinery casing be precisely aligned with corresponding features formed in stationary flowpath components.
Pressure levels for centrifugal compressors can be as high as 10,000 psi. This requires the machinery casing walls to be very thick. Due to the thickness of the casing walls, large machine tools are needed for machining various features into the machinery casing. In some situations, features cannot be machined into a desired location of the machinery casing from the exterior surface due to obstructions that prevent access by large machine tools. In these instances, the features must be machined from the interior surface of the machinery casing.
Machinery casings, like all pressure vessels, occasionally need to be drained or washed out. During operation, moisture, particulate matter and other undesirable contaminants may accumulate inside the machinery casing. These contaminants may damage or diminish the performance of the machinery and attached equipment. To drain contaminants form a machinery casing, flanged-type drain connections are commonly machined into the casing. These connections may be positioned at several locations on a casing or pressure vessel to permit contaminants to be purged. Similar types of connections may also be used at or near the top of the casing or pressure vessel to permit them to be washed out.
Numerous types of techniques for providing fluid connections with bodies such as machinery casings and pressure vessels are known. O-rings have been used for sealing fluid communicating apparatus. Mating tapered fittings have also been used for establishing connections in various fluid handling applications. Valves and couplings for fluid handling applications have been attached directly to the body of a machine by techniques such as welding. However, none of these connection techniques are suitable for high pressure applications such as centrifugal compressors where alignment of the connection to internal components is critically important. Limited success has been attained in using current techniques and apparatus in applications where a fluid communicating device must be precisely aligned with a component attached to the interior surface of a body. For example, welding a unitary fluid communicating apparatus onto the outside surface of a body may result in warping that can adversely affect alignment of the fluid communicating apparatus and an item attached to the interior surface of the body.
Accordingly, a need has arisen for an apparatus that is configured to overcome the shortcomings of prior art. In particular, a need has arisen for a fluid communicating apparatus for connecting to bodies such as machinery casings and pressure vessels. Fluid communicating apparatus according to the present invention will be well suited for use and installation in areas where conventional flanged connections cannot be used. Additionally, a fluid communicating apparatus is needed that is capable of aligning and sealing with an internal component of a machine. The fluid communicating apparatus will further be configured to decouple the components adapted for providing the structural integrity of the apparatus from those components adapted to provide the fluid communicating functionality.
One embodiment, accordingly, provides a fluid communicating apparatus that is configured to be received in a bore formed in a body. The apparatushas a portion adapted to provide structural integrity and a portion adapted to provide a seal between the apparatus and the bore of the body. To this end, a fluid communicating apparatus includes a housing having an elongated shaft portion, an interconnect flange connected at a first end of the shaft portion and a passage extending longitudinally through the shaft portion. An interconnect tube is received in the passage of the housing. The interconnect tube includes a sealing flange connected to seal against the first end of the shaft portion of the housing and a bore sealing portion connected to extend beyond a second end of the shaft portion.
A principal advantage of this embodiment is that the bore which receives the fluid communicating apparatus can be formed in locations of the body where obstructions or interferences prevent the machining of flange-type connections. Another advantage is that the housing may be constructed to withstand severe loads and impacts without these loads and impacts being directly transmitted to the interconnect tubing. Yet another advantage is that the bore and housing do not need to be precisely aligned to attain a reliable and effective seal between the interconnect tube and the body.